I am new at using GMT (Generic Mapping Tools) and I am wondering if it can use a shapefile of a hydrographical network.
Can I perhaps change my .shp to .gmt format and combine it with a GMT map? If ...

I have an eTrex 10. I'd like my GPS to remain in UTC (or GMT) time zone, but it does not offer this option as far as I can tell. I think "Western European" and "Ignore DST" is equivalent to GMT. Is ...